Olive oil is very high in compounds called phenols, which are potent antioxidants. It is also mainly made up of monounsaturated fat, the most important of which is called oleic acid, shown in research to be extremely heart healthy. Olive oil may also help to decrease the risk of colon and bowel cancer. But all olive oil is not created equal. The stuff you want is made from organic olives that are picked by hand; the oil is separated without the use of heat, hot water, or solvents, and it is left unfiltered. The first pressing produces the best stuff, known as “extra virgin” olive oil. Once you begin machine harvesting and processing with heat, you start damaging the health-promoting, delicate compounds in olive oil. So make sure to seek the extra virgin stuff—it’s worth the extra money.
Jonny Bowden, PhD, CNS, author of The 150 Healthiest Foods on Earth